Case insensitive version of the IN operator?

Hi, I was wondering if there is a case insensitive version of the IN operator, similar to ILIKE. Or is the IN itself case insensitive? It's mainly to avoid using nested OR's and ILIKE's if a case insensitive IN exists, to make the queries much simpler. Also, I don't want to use functions like lower as it's a big data set and the use of functions may make the queries even slower. Please advise. Thank you. Regards, Kevork Vartanian Technical Solutions Consultant kevork.vartanian@innotta.com.au | +61 406 776 789 | www.innotta.com.au